fix(app): adjust thinking budget tokens default and validation range

The default thinking budget tokens value was changed from 10000 to 1024 in base.py, and the minimum validation constraint was updated from 1024 to 1 in app_schema.py to allow smaller budgets while maintaining backward compatibility.

api/app/core/models/base.py

@@ -216,7 +216,7 @@ class RedBearModelFactory:
             # 深度思考模式：Claude 3.7 Sonnet 等支持思考的模型
             # 通过 additional_model_request_fields 传递 thinking 块，关闭时不传（Bedrock 无 disabled 选项）
             if config.deep_thinking:
-                budget = config.thinking_budget_tokens or 10000
+                budget = config.thinking_budget_tokens or 1024
                 params["additional_model_request_fields"] = {
                     "thinking": {"type": "enabled", "budget_tokens": budget}
                 }